Learn how to use the ClosedXML NuGet package to export data as a CSV or XLSX file for Excel from an ASP.NET Core application.

ASP.NET Core configuration providers read configuration data from common sources such as JSON files and databases. But you can use other sources by creating custom configuration providers.

Google is your friend. There are a ton of third party libs that will load an excel file into an ado.net dataset. From there you can use the select method to do your search.